Cut-off-valve mechanism.



N0. 70!,406. Patented June 3, I902. F. T. SHOEMAKER.

GUT-OFF VALVE MECHANISM.

(Application filed Ju ly 16, 1901.) (No mm 2 Shady-Sheet L No. 70l,406.Patented June 3, I902. F. T. SHOEMAKEH.

CUT-OFF VALVE MECHANISM.

(Application filed July 10, 1901.} (No Model.) 2 Sheets-Sheet 2.

f lg cgier TN: Nonms PETERS 00.4 mom-U790 wumusmu, I:v c4

UNITED STATES" PATENT FFICE.

FRANKLIN 'r. SHOEMAKER, OF CORINTH, MISSISSIPPI, ASSIGNOR OF ONE- HALFTO THOMAS K. JONES, OFCORINTH, MISSISSIPPI.-

CUT- OFF-VAL'VE MECHANISM.

SPECIFICATION forming part of Letters Patent No. 701,406, dated June 3,1902.

Application filed July 16,1901.

To (tZZ whom it 11-May concern:

Be it known that I, FRANKLIN T. Snot:- MAKER, a citizen of the UnitedStates, residing at Corinth, in the county of Alcorn and State ofMississippi, have-invented a new and useful Cut-Off-Valve'Mechanism forSteam-Engines, of which the followingis'a specification.

My invention is an improved cut-off-valve mechanism for steam-engines;and it'consists in the peculiar construction and combination of deviceshereinafter fully set forth and claimed.

One object of my invention is to combine with the cutoff valve of asteam-engine a cen trifugal governor adapted to adjust the said cut-offvalve in such manner as to increase or decrease the supply of steam tothe cylinder of the engine accordingly as the speed of the engine variesto regulate the speed thereof.

A further object of my invention is to effectimprovements in the meansfor adjusting the cut-off valv'es.

A further object of my invention is to provide means for automaticallycausing the cutoff valves to cut off the supply of steam to the cylinderin the event that the belt which drives the governor mechanism shouldbreak or slip from one of itspulleys, and hence cause the engine tostop..

In the accompanying drawings, Figure 1 is a side elevation of an engineprovided with my improved speed-governor and valve-gear. Fig. 2 is adetail longitudinal section, on a larger scale, taken through thecut-oil? valves and showing the steam and exhaust channels. Fig. 3 is adetail transverse vertical sectional view showing the connectionsbetween the screw-threaded cut-off-valve stem and the centrifugalmechanism. Fig. 4 is a longitudinal section through the tubular nut andscrew of the valve, and Fig. 5 is a transverse section of the same.

For the purposes ofthis specificationlshow my invention as used on, ahorizontalengine; but it will be understood that the same may beemployed in connection with a steam-engine of any type.

The bed of the engine is represented at a,

the cylinder at b, the steam-chest at c on one side of the cylinder, thecrank-shaft at cl, the

as No. 68,531. (No model.)

guideways at e, the cross-head at the pitman at g, the piston-rod at h,the eccentric at t', and the pitman attached to the eccentric and whichoperates the cut-oif valves at 71;.

In Fig. 2 of the drawings the steam-channels which lead from thesteam-chest to the ends of the cylinder are indicated at 1 and theexhaust-channels at 2, 3 being the steamportsande the exhaust-ports. Inconnection with the steam and exhaust ports I employ a pair of cut-offvalves 5, which maybe either of the form here shown or of any othersuitable form. Each of the cut-off valves is secured on a sleeve 6,which is provided on its ends with flanges 7, which bear against theends of the cut-off valves. The said sleeves 6 are interiorly threadedand are disposed on and engagedby screw-sleeves 8, the respectivescrew-threads'of which are reversely disposed, as shown in Fig. 2. Thesleeves 6 formltubular nuts which are engaged by and are adapted totravel longitudinally on screwsleeves 8. The latter are provided withplane longitudinal bores through which extends the Valve-stem or rod 9.The same is screw-threaded throughout a portion of its length, as at 10,said threaded portion of the said valvestem passing through but notengagingrt-he screwsleeves 8. Said threaded portiondof the valvestem isprovided on one side with'a longitudinal groove 11,- and the sameisengaged by feathers 12, with which the screw-sleeves are provided,whereby the latter are splined on the valve-stem, are adapted tomovelongitudinally thereon, and caused to rotate therewith. Each of thescrew-sleeves 8 is adjustable longitudinally on the threaded portion ofthe valve-stem by adj Listing-nuts 13, which bear against the ends ofthe screw-sleeves, as shown in Fig. 3, and by means of which the sleevesmay be adjusted longitudinally on the valve-stem toward and from eachother, as

will be understood. It will be further understood that by turningthevalve-stem -tlie,

screw-sleeves 8, which are respectivelyright and left hand screws, willcause the cut-off valves to move toward or from each other and vary theextent to which they open the steamports 3ateach stroke. Hence byappropriately turning the valve-stem the quantity of steam admitted tothe cylinder at each stroke of the piston may be regulated at will. Iwill now describe means whereby the valve-stem may be thus operated by acentrifugal-governor mechanism to regulate the speed of the engine.

The valve-stem 9 is connected to and operated by the pitman 7a, which isactuated by the eccentric t and imparts reciprocating motion to thecut-off valves when the engine is in operation. A pinion 14 is splinedon the valve-stem 9, as at 15, so that the valve-stem may reciprocate inthe pinion without moving the latter in a lateral direction. On one sideof the guideways e is a bracket 16, which has a vertical slot 17, inwhich the pinion 14 is disposed, the sides of the said slot formingstops which prevent lateral movement of the pinion. The latter isengaged by a verticallymovable rack-bar 18, which operates in guideways19, with which the bracket 16 is provided. From the lower end of thesaid vertically-movable rack-bar projects a depending stem 20. A spring,which is here shown as a coiled extensile spring .21, is on the saidstem and bears against the lower side of bracket 16 and an adjusting-nut22, which is screwed on the stem 20 and by means of which the tension ofthe said spring may be varied at will. It will be understood that thespring normally moves the rack-bar downwardly, and since the latter isin engagement with the pinion 14 normally prevents the valve-stem 9 fromturning. The centrifugal governor mechanism 23 may be either of theconstruction here shown or of any other suitable construction. Themovable element 21 thereof, which is here shown as a rod verticallymovable by the centrifugally actuated weighted arms 25, bears againstthe inner portion of a lever 26 on the upper side thereof. The saidlever is fulcrumed as at 27 and is connected to the rack-bar 18 by alink 28. A shaft 29, which has its bearings in the bracket 16, isprovided at its outer end with a pulley 30, and its inner end is gearedto the centrifugal governor mechanism by miter-gears 31. A pulley 32,which is on the crank-shaft cl, is connected to the pulley 30 by anendless belt 33, as shown in Fig. 1, and hence the centrifugal governormechanism is rotated when the engine is in operation.

The engine is initially adjusted with reference to the desired rate ofspeed and the load by appropriately turning the adjusting-nuts 13 and byadjusting the tension of the spring 21. At the desired rate of speed thelever 26 is balanced between the spring 21 and the vertically-movableelement 24 of the centrifugal mechanism. On an increase of the speed ofthe engine above the predetermined rate the weighted centrifugal arms 25depress the rod 24: and cause the lever 26 and link 28 to move therack-bar 18 upwardly, thereby turning the valve-stem 9 in the directionindicated by the arrow in Fig. 3, the right and left hand screw-sleeves011 the valve-stem causing the cut-0E valves to be moved from each otherin opposite directions, so that they will partly overlap the steam-ports3 at the ends of their strokes, and hence decrease the quantity of steamsupplied to the cylinder. On a decrease of the speed of the engine belowthe desired rate the valve-stem 0 will be partly turned in the reversedirection, as will be understood, to move the cut-off valves toward eachother, so that they will open the steam-ports 3 to a greater extent.

I will now describe means whereby in the event that the belt 33 shouldbreak or slip from one of the pulleys the valve-stem 9 will be turned tosuch an extent as to cause the cut-off valves to entirely out off theadmission of steam to the ends of the cylinder, and thereby stop theengine. The rock-shaft 34 is journaled in bearings 35, with which in theembodiment of my invention here shown the bracket 16 is provided. Thesaid rock-shaft has a cam 36, which engages or is adapted to engage thelever 26, and is further provided with a rock-arm 37, the lattercarrying an idle-pulley 38, which bears on the belt 33, as shown inFig. 1. Normally the rock-shaft 34 is inoperative; but in the event thatthe belt 33 breaks or slips from one of its pulleys the pulley 38 willdescend, owing to its weight, cause the arm 37 to turn the rock-shaft34, and the cam 36, which turns with the said rock-shaft, will engagewith the lever 26 and operate the latter in such manner as to cause therack and pinion to turn the valve-stem 9 to such an extent that thecut-off valves will entirely out off access of steam to the cylinderthrough the steam-ports 3.

I do not desire to limit myself to the precise construction andcombination of devices herein shown and described, as it is evident thatmodifications may be made therein without departing from the spirit ofmy invention.

Having thus described my invention, I claim-- 1. The combination of areciprocating valve-stem, right and left hand screw-sleeves splinedthereon, means to adjust said screw sleeves on said valve-stem, means toturn the latter, and cut-off valves engaged and operated by saidscrew-sleeves, whereby said outoff valves may be moved longitudinally inopposite directions by turning said valvestem, for the purpose setforth, substantially as described.

2. The combination of a reciprocating valve-stem, right and left handscrew-sleeves splined thereon, means to adjust said screwsleeves on saidvalve-stem, means to turn the latter, cut-off valves engaged andoperated by said screw-sleeves,whereby said cut-off valves may be movedlongitudinally in opposite directions by turning said valve-stem, and acentrifugal mechanism and connections between the same and saidvalve-stem, to automatically turn the latter, substantially asdescribed.

3. The combination of a reciprocating screw-threaded valve-stem, rightand left IIO hand screw-sleeves splined thereon, but not engaged by'thescrew-thread thereof, adjusting-nuts on said threaded valve-stem toadjust said screw-sleeves, and out-off valves engaged by said right andleft hand screwsleeves,for the purpose set f0rtl1,substantiall y asdescribed.

4. In an engine, the combination of cut-oil": valves, a reciprocatingrevoluble valve-stein, to move said valves reversely, for the purposeset forth, a spring to turn said valve-stem in one direction, and acentrifugal mechanism to turn said stem in the reverse direction,substantially as described.

5. In an engine,the combination of cut-off valves, a reciprocatingrevoluble valve-stein, to move said valves reversely, for the purposeset forth, a spring to turn said valve-stem in one directiomacentrifugal mechanism to turn said stem in the reverse direction, andmeans to vary the power of said spring, substantially as described.

6. In an engine, the combination of cut-off valves, a reciprocatingrevoluble valve-ste m,

to move said valves reversely, for the purpose set forth, and means,automatically operated, on an abnormal increase of speed of the engine,to turn said stem and cause said valves to cut off the supply of steamto the cylinder, substantially as described.

7. In an engine, the combination of cnt-ofi valves, operative on thesteam and exhaust ports of the cylinder, a speed mechanism to adjustsaid valves automatically, a belt to drive said speed mechanism, anormally idle element supported by said belt, and connections betweensaid normally idle element and said valves, to operate the latter whensaid normally idle element is released by said belt, substantially asdescribed.

In testimony that I claim the foregoing as my own I have hereto affixedmy signature in the presence of two witnesses.

FRANKLIN T. SHOEMAKER.

Witnesses:

W. F. WALLACE, W. B. WILsON.

